Dynamically Reassigning a High-Noise Frequency Segment from a First Access Node to a Second Access Node

ABSTRACT

A method and system to dynamically reassign RF spectrum from a first access node to a second access node, where the first access node provides service on a first carrier having a carrier bandwidth. An example method includes (i) selecting a frequency portion of the carrier bandwidth to reassign, the selecting being based on the frequency portion having higher determined noise than one or more other frequency portions of the carrier bandwidth, and (ii) based on the selecting, reassigning the selected frequency portion from the first access node to the second access node to be used by the second access node as at least part of a second carrier on which to provide service. Upon reassigning of the selected frequency portion, the second access node could then provide service on the reassigned portion and the first access node could continue to provide service on a remainder of the first carrier.

REFERENCE TO RELATED APPLICATION

This is a continuation of U.S. patent application Ser. No. 17/305,969,filed Jul. 19, 2021 the entirety of which is hereby incorporated byreference.

BACKGROUND

A typical wireless communication system includes a number of accessnodes that are configured to provide wireless coverage areas, referredto as cells, in which user equipment devices (UEs) such as cell phones,tablet computers, machine-type-communication devices, tracking devices,embedded wireless modules, and/or other wirelessly equippedcommunication devices (whether or not user operated), can operate. Eachaccess node could be coupled with a core network that providesconnectivity with various application servers and/or transport networks,such as the public switched telephone network (PSTN) and/or the Internetfor instance. With this arrangement, a UE within coverage of the systemcould engage in air interface communication with an access node andcould thereby communicate via the access node with various applicationservers and other entities.

Such a system could operate in accordance with a particular radio accesstechnology (RAT), with communications from an access node to UEsdefining a downlink or forward link and communications from the UEs tothe access node defining an uplink or reverse link.

Over the years, the industry has developed various generations of RATs,in a continuous effort to increase available data rate and quality ofservice for end users. These generations have ranged from “1G,” whichused simple analog frequency modulation to facilitate basic voice-callservice, to “4G”—such as Long Term Evolution (LTE), which nowfacilitates mobile broadband service using technologies such asorthogonal frequency division multiplexing (OFDM) and multiple inputmultiple output (MIMO). And recently, the industry has completed initialspecifications for “5G” and particularly “5G NR” (5G New Radio), whichmay use a scalable OFDM air interface, advanced channel coding, massiveMIMO, beamforming, and/or other features, to support higher data ratesand countless applications, such as mission-critical services, enhancedmobile broadband, and massive Internet of Things (IoT).

In accordance with the RAT, each cell could operate on a radio-frequency(RF) carrier, which could be frequency division duplex (FDD), definingseparate frequency channels for downlink and uplink communication, ortime division duplex (TDD), with a single frequency channel multiplexedover time between downlink and uplink use. And each such frequencychannel could be defined as a specific range of frequency (e.g., in RFspectrum) having a bandwidth and a center frequency and thus extendingfrom a low-end frequency to a high-end frequency.

Each carrier could be defined within an industry standard frequencyband, by its frequency channel(s) being defined within the frequencyband. Examples of such frequency bands include (i) bands 2, 4, 12, 25,26, 66, 71, and 85, supporting FDD carriers (ii) band 41, supporting TDDcarriers, and (iii) bands n258, n260, and n261, supporting FDD and TDDcarriers, among numerous other possibilities. Further, each cell couldhave a physical cell identity (PCI) or the like that identifies the cellon the carrier, to help distinguish adjacent or otherwise nearby cellsthat operate on the same carrier as each other. Accordingly, each cellcould be characterized by a respective combination of its carrier andits PCI.

On the downlink and uplink, the air interface of each cell could beconfigured in a specific manner to define physical resources forcarrying information (e.g., user-plane data and control-plane signaling)wirelessly between the access node and UEs.

In a non-limiting example implementation, for instance, the airinterface of each cell could be divided over time into frames,subframes, and symbol time segments, and over frequency into subcarriersthat could be modulated to carry data. The example air interface couldthus define an array of time-frequency resource elements, with eachresource element spanning a respective symbol time segment and occupyinga respective subcarrier, and the subcarrier of each resource elementcould be modulated to carry information.

In addition, certain groups of these resource elements on the downlinkand uplink of the example air interface could then be designated forspecial use.

For instance, on the downlink, certain resource elements per subframecould be generally reserved to define a physical downlink controlchannel (PDCCH) for carrying control signaling such as schedulingdirectives from the access node to served UEs, and other resourceelements per subframe could be generally reserved to define a physicaldownlink shared channel (PDSCH) in which the resource elements could begrouped to define physical resource blocks (PRBs) that could beallocated on an as needed basis to carry data communication from theaccess node to UEs.

Further, among these generally reserved downlink resources, certainresource elements could be excluded from the PDCCH and PDSCH andreserved for other use. For instance, in LTE, (i) certain resourceelements per frame could be reserved to provide primary and secondarysynchronization signals (PSS and SSS) that UEs could detect as anindication of carrier presence and to establish frame timing, (ii) otherresource elements per frame could be reserved to provide physicalbroadcast channel (PBCH) messaging, including a master information block(MIB) and various system information blocks (SIBs), that UEs could readto determine carrier bandwidth and other carrier and system information,and (iii) other resource elements per frame could be reserved to providea cell specific reference signal (CRS) that UEs could measure as a basisto gauge coverage strength on the carrier. And in NR, certain resourceelements per frame could be reserved to define a synchronization signalblock (SSB) that carries PSS, SSS, and PBCH of the NR carrier and thatUEs can also measure to gauge coverage strength.

And likewise, on the uplink, certain resource elements could be reservedto define an uplink control channel (PUCCH), and other resource elementsbetween could be generally reserved to define a physical uplink sharedchannel (PUSCH) in which the resource elements could be grouped todefine PRBs that could be allocated on an as needed basis to carry datacommunications from UEs to the access node. And within these generallyreserved ranges, certain resource elements could similarly be excludedfrom the PUCCH and PUSCH and reserved for other use, such as to carryuplink reference signals and random-access messaging, among otherpossibilities. OVERVIEW In example operation, when a UE enters intocoverage of such a network, the UE could initially scan for and detectthreshold strong coverage of a cell provided by an access node. And theUE could then engage in random-access and connection signaling, such asRadio Resource Control (RRC) signaling, with the access node toestablish an air-interface connection (e.g., RRC connection) throughwhich the access node will then serve the UE in the cell.

Further, if the UE is not already registered for service with the corenetwork, the UE could transmit to the access node an attach request,which the access node could forward to a core-network controller forprocessing. And the core-network controller and access node could thenresponsively coordinate setup for the UE of one or more user-planebearers, each including an access-bearer that extends between the accessnode and a core-network gateway system providing connectivity with atransport network, and a data-radio-bearer (DRB) that extends over theair between the access node and the UE.

Once the UE is so connected and registered, the access node could thenserve the UE in a connected mode over the established air-interfaceconnection, coordinating downlink air-interface communication of packetdata to the UE and uplink air-interface communication of packet datafrom the UE.

With the example air interface described above, for instance, whenpacket data for the UE arrives at the core network from a transportnetwork, the data could flow to the UE's serving access node, and theaccess node could then allocate one or more downlink PRBs to carry thedata to the UE and could transmit to the UE a scheduling directivedesignating the allocated PRBs, and the access node could thenaccordingly transmit the data to the UE in the allocated PRBs. Likewise,when the UE has data to transmit on the transport network, the UE couldtransmit a scheduling request to the access node, the access node couldresponsively allocate one or more uplink PRBs to carry the data from theUE and could transmit to the UE a scheduling directive designating theallocated PRBs, and the UE could then accordingly transmit the data tothe access node in the allocated PRBs.

As the industry advances from one RAT to another, wireless operators mayface challenges regarding RF spectrum allocation. Without limitation,this is particularly the case with the advance from 4G LTE to 5G NR.Although 5G NR coverage is commonly provided at higher frequencies withgreater bandwidth, those higher frequencies also suffer from higher pathloss and associated reduced coverage area. Therefore, wireless operatorsmay desire to implement 5G NR at lower frequencies. But the lowerfrequencies tend to be used for 4G LTE service. Further, operators mayhave limited licensed RF spectrum.

One solution to this problem could be for a wireless operator tostatically reassign some of its licensed RF spectrum from 4G LTE use to5G NR use. For instance, if the operator had devoted spectrum in a givenband to 4G LTE service, the operator could statically reassign one ormore carriers in that band to be used for 5G NR service instead.Unfortunately, however, this static reassignment of spectrum could poseproblems for 4G LTE-only UEs, possibly limiting their availablethroughput.

An improved solution may be dynamic spectrum sharing (DSS). With DSS,the operator could dynamically allocate some of its RF spectrum from 4GLTE use to 5G NR use, perhaps increasing the allocation as 5G NR devicepenetration increases. For instance, as to a given 4G LTE carrier, theoperator could dynamically assign certain subframes and/or ranges ofPRBs of the carrier for 5G NR use. An operator could usefully implementDSS where the operator would provide overlapping 4G LTE and 5G NRcoverage, such as with collocated 4G LTE and 5G NR access nodes thatradiate in largely the same direction as each other, among otherpossibilities.

An example DSS implementation with 4G LTE and 5G NR, a 4G LTE accessnode (4G evolved Node-B (eNB)), and/or an associated computing system,could manage spectrum reassignment to a 5G NR access node (5Gnext-generation Node-B (gNB)). In particular, the 4G eNB could beconfigured by default to provide 4G LTE service on a particular carrierthat has an associated carrier bandwidth and structure as noted abovefor instance. And the 4G eNB could dynamically reassign a portion ofthat carrier to the 5G gNB for use by the 5G gNB to provide 5G NRservice. For instance, the 4G eNB could reassign a specific range ofPRBs of the carrier, perhaps in specific subframes, to the 5G gNB foruse as a 5G NR carrier. Further, the 4G eNB could dynamically thisspectrum allocation periodically, such as on a per frame or per subframebasis, among other possibilities.

This DSS implementation could enable UEs that support both 4G LTE and 5GNR service to make good use of the dynamically defined 5G NR carrier. Inpractice, for instance, when the 4G eNB dynamically reassigns thespectrum to define the 5G NR carrier, the 4G eNB could inform suchdual-RAT UEs that the 5G NR carrier exists. By way of example, the 4GeNB could broadcast in a 4G LTE SIB message an indication of the timeand frequency position of the SSB that the 5G gNB will broadcast on the5G NR carrier, or the 4G eNB could directly report that SSB position tothe 4G eNB's served UEs that are 5G NR capable. Each such UE could thenread the SSB to determine configuration of the dynamically defined 5G NRcarrier and could then work to acquire connectivity with the 5G gNB onthat 5G NR carrier.

A technological issue that can arise with such DSS implementations,however, is that the 4G eNB may end up reassigning for 5G NR use somerelatively high-quality RF spectrum of the carrier, thus removing thatrelatively high-quality RF spectrum from availability for use to serve4G LTE-only UEs. The quality level at issue here could relate to thelevel of noise present on the carrier. Across its bandwidth, a carriermay have varying levels of noise. Portions of the carrier, such asparticular PRBs, that have higher level of noise than other portions ofthe carrier, may pose greater issues with air-interface communication,thus limiting throughput.

If the 4G eNB reassigns for 5G NR use some relatively high-quality RFspectrum of the carrier, e.g., a range of PRBs having relatively lowlevels of noise compared with other PRBs of the carrier, that may leavethe lower-quality (e.g., higher noise) portions of the carrier for useto serve 4G LTE-only UEs. And that may result in the 4G LTE-only UEssuffering from possibly reduced throughput than they could have attainedwith service on the higher-quality portions of the carrier.

The present disclosure provides a mechanism to help address thistechnical issue.

In accordance with the disclosure, when a first access node (e.g., a 4GeNB) is going to dynamically reassign a frequency portion of a carrierfor use by a second access node (e.g., a 5G gNB), the first access nodewill select the frequency portion based on the frequency portion havinga relatively high level of noise compared with one or more otherfrequency portions of the carrier.

For instance, if the carrier defines a plurality N of PRBs and the firstaccess node will dynamically reassign a quantity Q of those PRBs for useby the second access node, the first access node could determine thelevel of noise respectively of each of various candidate sets of Q ofthe PRBs, and the first access node could select a set based on the sethaving the highest determined level of noise among the candidate set orbased on the set having a higher determined level of noise than one ormore other sets of the candidate sets. And based on that selection, thefirst access node could then dynamically reassign a frequency portiondefined by that selected set of Q of the PRBs for use by the secondaccess node.

Optimally, by selectively reassigning for use by the second access nodethe set of Q of the PRBs having the highest determined level of noise orhaving higher determined noise than another candidate set, the firstaccess node can help to retain higher quality PRBs of the carrier foruse to serve UEs itself, perhaps to serve UEs that are capable of beingserved by the first access node and are not capable of being served bythe second access node.

These as well as other aspects, advantages, and alternatives will becomeapparent to those of ordinary skill in the art by reading the followingdetailed description, with reference where appropriate to theaccompanying drawings. Further, it should be understood that thedescriptions provided in this overview and below are intended toillustrate the invention by way of example only and not by way oflimitation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a simplified block diagram of an example network arrangementin which features of the present disclosure can be implemented.

FIG. 2 is a flow chart depicting a method that can be carried out inaccordance with the disclosure.

FIG. 3 is a simplified block diagram of an example access node operablein an example implementation.

FIG. 4 is a simplified block diagram of an example computing systemoperable in an example implementation.

DETAILED DESCRIPTION

An example implementation will now be described in the context of asystem supporting both 4G LTE and 5G NR as noted above. But it should beunderstood that the disclosed principles could extend to apply in otherscenarios as well, such as with other RATs, and with other networkconfigurations, among other possibilities.

Further, it should be understood that other changes from the specificarrangements and processes described are possible. For instance, variousdescribed entities, connections, operations, and other elements could beadded, omitted, distributed, re-located, re-ordered, combined, orchanged in other ways. In addition, various operations described asbeing performed by one or more entities could be implemented in variousways, such as by a processing unit executing instructions stored innon-transitory data storage, along with associated circuitry or otherhardware, among other possibilities.

Referring to the drawings, FIG. 1 is a simplified block diagram of anexample network arrangement having a 4G eNB 12 and a 5G gNB 14. Theseaccess nodes could be macro access nodes of the type configured toprovide a wide range of coverage or could take other forms, such assmall cell access nodes, relays, femtocell access nodes, or the like,possibly configured to provide a smaller range of coverage, and theaccess nodes could take different forms than each other. Further, theaccess nodes could be collocated with each other, e.g., at a common cellsite with collocated RF points of origin, or could be separatelylocated. Either way, the access nodes could be optimally configured toprovide spatially overlapping coverage.

In the example illustrated, the 4G eNB 12 is configured to provide 4Gcoverage and service on one or more 4G carriers 16, and the 5G gNB 14 isconfigured to provide 5G coverage and service on one or more 5G carriers18, at least one of which may be dynamically defined per the presentdisclosure.

To facilitate providing service and coverage on the illustratedcarriers, the access nodes could each have a respective antennastructures, such as an antenna array, that is configured to transmit andreceive electromagnetic signals in a region defined by an antennapattern or radiation pattern, or the access nodes could share portionsof a common antenna array for this purpose. Further, the access nodescould include other communication equipment, such as baseband units,radio heads, power amplifiers, and the like.

The air interface on each of these carriers could be structured asdescribed above by way of example, being divided over time into frames,subframes, and symbol time segments, and over frequency intosubcarriers, thus defining an array of air-interface resource elementsgrouped into PRBs allocable by the respective access node as notedabove, for use to carry data to or from served UEs. Carrier-structureand/or service on the 4G and 5G air-interfaces, however, could differfrom each other in various ways now known or later developed, such aswith one implementing variable subcarrier spacing and the other havingfixed subcarrier spacing, with one having flexible TDD configuration andthe other having fixed TDD configuration, with one having differentsubcarrier spacing and/or symbol time segment length than the other,and/or with one making different use of MIMO technologies than theother, among other possibilities.

As further shown in FIG. 1 , the example arrangement includes two corenetworks, designated as a 4G core network 20 and a 5G core network 22,each providing connectivity with an external transport network 24 suchas the Internet for instance.

Each of these core networks could be a packet-switched networksupporting virtual-packet tunnels or other interface between networknodes. And each core network could include both a user-plane subsystemthrough which UE bearer communications could flow to and from thetransport network 24, and a control-plane subsystem supporting functionssuch as UE authentication, mobility management, and bearer management,among others. In particular, the 4G core network 20 is shown including auser-plane subsystem 26 and a control-plane subsystem 28, and the 5Gcore network 22 is shown including a user-plane subsystem 30 and acontrol-plane subsystem 32. The 4G and 5G core networks, however, maydiffer from each in various ways, with the 5G core network offeringcertain advantages. For instance, the 5G core network 22 may providegreater separation of control-plane and user-plane functions and mayfacilitate advanced slicing or other options that offer improved qualityof service and other benefits compared with the 4G core network 20.

In the example arrangement shown, the 4G eNB 12 is interfaced with the4G core network 20, so that UEs served by the 4G eNB 12 may be served inturn by the 4G core network 20, and the 5G gNB 14 is interfaced with the5G core network 22, so that UEs served by the 5G gNB 14 may be served inturn by the 5G core network 22. Further, the 5G gNB 14 may also beinterfaced with the 4G core network 20 as shown, to support 4G-5G dualconnectivity where a UE is served concurrently by both the 4G eNB 12 andthe 5G gNB 14, and in turn by the 4G core network 20. In addition, asshown, the 4G eNB 12 and 5G gNB 14 could have a communication interface(e.g., an X2 interface or Xn interface) 38 with each other.

FIG. 1 illustrates a number of example UEs 36 that may from time to timebe within coverage of both the 4G eNB 12 and the 5G gNB 14. Each such UEcould take any of the forms noted above among other possibilities.Further, some such UEs may be 4G-only in that the UEs support 4G LTEservice but not 5G NR service, whereas other such UEs may support 5G NRservice, perhaps being backwards compatible to support 4G LTE service aswell, and perhaps supporting DSS as described herein. To facilitate 4GLTE service, a UE could include a 4G LTE radio and associated circuitry.And to facilitate 5G NR service, a UE could include a 5G NR ratio andassociated circuitry.

In an example implementation, when the UE is within coverage of thissystem, the UE may acquire connectivity with either the 4G eNB 12 or the5G gNB 14. The choice of which access node the UE would connect withcould depend on various factors, such whether the UE is set to preferone RAT over the other and/or which access node provides strongercoverage, among other possibilities.

If the UE discovers threshold strong coverage of the 4G eNB 12 on a 4Gcarrier 16 and decides to connect with the 4G eNB 12, the UE may thenresponsibly engage in random access and RRC signaling with the 4G eNB 12to establish a 4G connection between the UE and the 4G eNB 12 on that 4Gcarrier 16. And once the UE is connected with the 4G eNB 12, the UEcould then transmit to the 4G eNB 12 an attach or registration message,which the 4G eNB 12 could forward to the control-plane subsystem 30 ofthe 4G core network 20 for processing. Upon authenticating andauthorizing the UE for service, the control-plane subsystem 30 and the4G eNB 12 could coordinate setup for the UE of at least one user-planebearer through the user-plane subsystem 26 of the 4G core network 20,enabling the UE to communicate on transport network 24.

Once the UE is connected with the 4G eNB 12 and registered with the 4Gcore network 20, the 4G eNB 12 could then provide the UE with wirelesspacket-data communications as noted above. For instance, when theuser-plane subsystem 26 of the 4G core network 20 receives data from thetransport network 24 for transmission to the UE, that data could flowvia the UE's bearer to the 4G eNB 12, and the 4G eNB 12 could coordinatetransmission of that data from the 4G eNB 12 to the UE on downlink PRBsof the 4G carrier 16 of the UE's 4G connection. And when the UE has datafor transmission on the transport network 24, the UE could transmit ascheduling request to the 4G eNB 12, the 4G eNB 12 could coordinatetransmission of that data from the UE to the 4G eNB 12 on uplink PRBs ofthe 4G carrier 16, and the data could then flow via the UE's accessbearer through the user-plane subsystem 26 of the 4G core network 20,for output on the transport network 24.

Whereas, if the UE discovers threshold strong coverage of the 5G gNB 14on a 5G carrier 18 and decides to connect with the 5G gNB 14, then theUE may responsively engage in random access and RRC signaling with the5G gNB 14 to establish a 5G connection between the UE and the 5G eNB 14on that 5G carrier 18. And once the UE is connected with the 5G gNB 14,the UE could then transmit to the 5G eNB 14 an attach or registrationrequest message, which the 5G gNB 14 could forward to the control-planesubsystem 34 of the 5G core network 22 for processing. And uponauthenticating and authorizing the UE for service, the control-planesubsystem 34 and the 5G gNB 14 could coordinate setup for the UE of atleast one user-plane bearer through the user-plane subsystem 32 of the5G core network 22, likewise enabling the UE to communicate on transportnetwork 24.

Once the UE is connected with the 5G gNB 14 and registered with the 5Gcore network 22, the 5G gNB 14 could then similarly provide the UE withwireless packet-data communications as noted above. For instance, whenthe user-plane subsystem 32 of the 5G core network 22 receives data fromthe transport network 24 for transmission to the UE, that data couldflow via the UE's bearer to the 5G gNB 14, and the 5G gNB 14 couldcoordinate transmission of that data from the 5G gNB 14 to the UE ondownlink PRBs of the 5G carrier 18 of the UE's 5G connection. And whenthe UE has data for transmission on the transport network 24, the UEcould transmit a scheduling request to the 5G gNB 14, the 5G gNB 14could coordinate transmission of that data from the UE to the 5G gNB 14on uplink PRBs of the 5G carrier 18, and the data could then flow viathe UE's access bearer through the user-plane subsystem 32 of the 5Gcore network 20, for output on the transport network 24.

In relation to the attachment process, as to 4G or 5G service, the UE'sserving access node may also obtain capabilities data regarding the UE.For instance, the user-plane subsystem of the associated core networkmay obtain a set of capabilities data for the UE from a central server,registry, or directory, and may provide that capabilities data to theaccess node. Alternatively or additionally, the UE may transmit suchcapabilities data to the access node. The access node may then store thecapabilities data for reference when serving the UE. In an exampleimplementation, this capabilities data could indicate which RATs the UEsupports and whether the UE supports DSS, among other capabilitiesinformation.

In line with the discussion above, the 4G eNB 12 could be configured todynamically reassign a portion of at least one 4G carrier 16 for use todefine part or all of a 5G carrier 18 on which the 5G gNB 14 canoperate. Further, the 4G eNB 12 select the portion to so reassign, withthe selection being based on the level of noise on the portion comparedwith the level of noise respectively on each of one or more otherportions of the 4G carrier. And still further, the 4G eNB 12 coulddetermine what size portion to so reassign, with the determination beingbased on consideration of the level of load of the 5G gNB 14, such asselecting a larger portion to so reassign if the 5G gNB is more loadedfor instance.

Without limitation, in an example implementation, the portion of the 4Gcarrier 16 that the 4G eNB 12 would dynamically reassign to the 5G gNB14 could be a frequency-contiguous group of one or more PRBs selected(as a proper subset) from the carrier's bandwidth. This selected groupof PRBs could thus define a selected narrowband frequency range fromwithin the wider bandwidth of the 4G carrier 16. If the 4G carrier 16 isan FDD carrier, this could be done respectively for the downlink channeland the uplink channel. Whereas, if the 4G carrier 16 is a TDD carrier,this could be done generally encompassing both the downlink and theuplink. Further, the reassignment of this frequency range could be doneon a per-subframe or other per-time basis, such as to take effect onlyin certain subframes per frame, among other possibilities.

Normally, this frequency range would be devoted as part of the 4Gcarrier 16. The dynamic reassignment, however, could effectively convertthe frequency range instead into a 5G carrier 18 or part of a 5G carrier18. Further, the 4G eNB 12 could carry out this dynamic reassignmentperiodically or in response to one or more other triggers, and each timethe 4G eNB carries out the process, the 4G eNB 12 may assign a differentfrequency range, selected in accordance with the present disclosure.

In practice, the 4G eNB 12 could determine first how wide of a swath offrequency to dynamically reassign to the 5G gNB 14. As noted above, the4G eNB 12 could make this determination based on consideration of loadof the 5G gNB 14. To facilitate this, the 5G gNB 14 could periodicallyreport over interface 38 to the 4G eNB 12 the level of load of the 5GgNB 14, such as the quantity of data served by the 5G gNB 14 per unittime and/or the quantity of UEs served by the 5G gNB 14, among otherpossible load metrics. The 5G gNB 14 may report this load data invarious forms, representing a latest such load metric and/or statisticaltrend data representing typical load of the 5G gNB 14 for the currenttime of day, for instance. Further, the 4G eNB 12 could receive thisdata and may itself roll up the data to establish statistical trend datarepresenting typical load of the 5G gNB 14 per time of day for instance.

Given the latest level of load of the 5G gNB 14 and/or predicting whatthe level of load of the 5G gNB 14 is likely to be for a current time ofday based on past load data, the 4G eNB 12 could then determine aquantity Q of PRBs to include in a set of PRBs of 4G carrier 16 that the4G eNB 12 will dynamically reassign to the 5G gNB 14. For instance, the4G eNB 12 could determine a greater quantity Q of PRBs, defining a widerencompassing swath of RF spectrum to dynamically reassign, if and whenthe load of the 5G gNB 14 is higher, and the 4G eNB 12 could determine alesser quantity Q of PRBs, defining a narrower encompassing swath of RFspectrum to dynamically reassign, if and when the load of the 5G gNB 14is lower. To facilitate this, the 4G eNB 12 could be provisioned withmapping data (e.g., a table) that maps various ranges of load toassociated quantities Q of PRBs, and the 4G eNB 12 could refer to thatmapping data to determine a quantity Q of PRBs based on the level ofload of the 5G gNB 14.

At issue for the 4G eNB 12 may then be which contiguous set of Q of thePRBs of carrier 16 the 4G eNB 12 should select to be dynamicallyreassigned to the 5G gNB 14.

As noted above, the 4G eNB 12 could make this selection based on aconsideration of the level of noise respectively of each of variouscandidate sets of Q of the PRBs of the carrier 16. In an exampleimplementation, for instance, the 4G eNB 12 could divide the PRBs ofcarrier 16 into mutually exclusive sets of Q PRBs, or the 4G eNB 12could otherwise define candidate sets of Q PRBs of the carrier 16,possibly sets that are not mutually exclusive but that rather overlapwith each other to some extent. And the 4G eNB 12 could evaluate thelevel of noise respectively on each such candidate set of PRBs.

The 4G eNB 12 could determine the level of noise respectively of eachcandidate set of PRBs in various ways, possibly considering noise perPRB on the downlink and/or noise per PRB on the uplink.

On the downlink, for instance, the 4G eNB 12 could determine the levelof noise per downlink PRB by having one or more served UEs measure andreport to the 4G eNB 12 a level of signal-to-interference-plus-noiseratio (SINR) of transmission (e.g., reference signal transmission orother transmission) from the 4G eNB 12 respectively per PRB on thecarrier. For instance, the 4G eNB 12 could transmit to each such servedUE an RRC connection reconfiguration message that directs the UE to takeand report such measurements, and the UEs could responsively take suchmeasurements and transmit RRC messages to the 4G eNB 12 providing themeasurements. The 4G eNB 12 could then effectively deem the level ofnoise per PRB to be an inverse of such reported SINR for that PRB. Andthe 4G eNB 12 could maintain in data storage a rolled up average orother statistical measures of this or other such noise per PRB, such asover a recent sliding window of time for instance.

And on the uplink, the 4G eNB 12 could determine the level of noise peruplink PRB by itself measuring the level of noise per uplink PRB. Forinstance, the access node could measure the energy level above abaseline level on each PRB, as a representation of reverse noise rise(RNR) or the like (e.g., the level of energy that the 4G eNB 12 measureson useable resource elements of the PRB at times when no communicationis scheduled on the resource elements), among other possibilities. Andthe 4G eNB 12 could likewise maintain in data storage a rolled upaverage or other statistical measure of this or other such noise perPRB, also perhaps over a recent sliding window of time.

Given this or other such data indicating the level of noise per PRB onthe carrier, the 4G eNB 12 could then compute a level of noiserespectively of each candidate set of Q of the PRBs. For instance, the4G eNB 12 could compute the level of noise per candidate set of PRBs asthe total of the level of noise of its constituent PRBs or as theaverage of the level of noise of its constituent PRBs, among otherpossibilities.

The 4G eNB 12 could then select one of the candidate sets of PRBs to bethe set of PRBs defining the frequency portion of carrier 16 that the 4GeNB 12 will dynamically reassign to 5G gNB 14 for use to provide 5Gservice. As noted above, for instance, the 4G eNB 12 could select one ofthe candidate sets of PRBs based on the candidate set having the highestdetermined level of noise among the candidate sets of PRBs of thecarrier 16, or the 4G eNB 12 could select one of the candidate sets ofPRBs based on the candidate set having higher determined noise than atleast one other of the candidate sets of PRBs of the carrier 16.

Once the 4G eNB 12 has selected this frequency portion of carrier 16 todynamically reassign to the 5G gNB 14 for use to provide 5G service, the4G eNB 12 could then engage in the dynamic reassignment. Dynamicallyreassigning this spectrum could occur in a standard manner. Withoutlimitation, for instance, the 4G eNB 12 could engage in signaling withthe 5G gNB 14 to inform the 5G gNB 14 of the assigned frequency portionas a 5G carrier 18 and to establish the time and frequency position onthat carrier of the SSB that the 5G gNB 14 will broadcast to enable UEsto detect and connect on the carrier. Further, the 4G eNB 12 couldbroadcast in a SIB2 message, or unicast to its served UEs (perhapsspecifically to UES selected by the 4G eNB 12 based on theircapabilities data indicating that they support DSS), an indication ofthe 5G carrier 18 such as its SSB position, to enable the UEs to detectand connect on the carrier.

The 5G gNB 14 may then commence operation on the newly defined 5Gcarrier encompassing the frequency portion dynamically reassigned by the4G eNB 12. Further, one or more UEs served by the 4G eNB 12 and/or privyto the SIB2 broadcast from the 4G eNB 12, among other possibilities, maythen scan for and discover the SSB of the new carrier 18 and then workwith the 5G gNB 14 to establish a 5G connection and to be served by the5G gNB 14 on the new carrier 18.

Further, upon so dynamically reassigning the selected frequency portionto the 5G gNB 14, the 4G eNB 12 could then continue to provide 4Gservice on just a remainder of the 4G carrier 16. For instance, whilebefore the reassignment the 4G eNB 12 may have allocated any of thevarious PRBs of the 4G carrier 16 for use to carry bearer communicationsbetween the 4G eNB 12 and its served UE(s), after the reassignment, the4G eNB 12 may then allocate for such use any of the various PRBs otherthan those of the reassigned selected frequency portion, forgoingallocation of the reassigned PRBs for the time being.

In an example implementation, the 4G eNB 12 could carry out this dynamicspectrum reassignment process just when the 4G eNB 12 is serving atleast one UE whose capability data indicates that the UE is DSS capable,or just when the 4G eNB 12 is serving at least some other predefinedthreshold number of UEs whose capability data indicates that they areeach DSS capable. Thus, the 4G eNB 12 could regularly monitorcapabilities data of its served UEs to so determine when to carry outthis process and could carry out the process accordingly based on theextent to which the 4G eNB 12 is serving one or more DSS-capable UEs.

Further, as noted above, the dynamic reassignment of RF spectrum couldbe for use in just certain subframes. For instance, as to every10-subframe frame on the 4G carrier 16, the 4G eNB 12 could dynamicallyreassign a frequency portion in just one or two of the subframes,leaving the more full RF spectrum available for 4G use in the othersubframes. Other examples are possible as well.

FIG. 2 is next a flow chart depicting a method that could be carried outin accordance with the present disclosure, to dynamically reassign RFspectrum from a first access node to a second access node in a scenariowhere the first access node provides wireless communication service on afirst carrier that has a carrier bandwidth. As noted above, this methodcould be carried out by the first access node and/or by anothercomputing system.

As shown in FIG. 2 , at block 40, the method includes selecting afrequency portion of the carrier bandwidth to reassign from the firstaccess node to the second access node, with the selecting being based onthe frequency portion having a higher determined noise than one or moreother frequency portions of the carrier bandwidth. And at block 42, themethod includes, based on the selecting, reassigning the selectedfrequency portion from the first access node to the second access nodeto be used by the second access node as at least part of a secondcarrier on which to provide wireless communication service. Uponreassigning of the selected frequency portion, the second access nodecould then provide wireless communication service on the reassignedfrequency portion, and the first access node could continue to providewireless communication service on a remainder of the first carrier.

In line with the discussion above, the method could additionally involvedetermining a width of frequency to reassign from the first access nodeto the second access node, with the determining being based on a levelof load of the second access node. And in that case, the selecting ofthe frequency portion of the carrier bandwidth could involve, based onthe determining of the width of frequency to reassign, selecting as thefrequency portion of the carrier bandwidth a frequency portion of thedetermined width. Without limitation, for instance, the carrierbandwidth could define a plurality of PRBs, and the act of determiningthe width of frequency could involve determining a quantity of the PRBsthat could define the frequency portion.

As further discussed above, the act of selecting the frequency portionbased on the frequency portion having a higher determined noise than oneor more other frequency portions of the carrier bandwidth could involveselecting the frequency portion based on a determination that thefrequency portion has a highest determined noise of a plurality offrequency portions of the carrier bandwidth.

Further, as discussed above, the act of selecting the frequency portionbased on the frequency portion having a higher determined noise than oneor more other frequency portions of the carrier bandwidth could be basedon uplink noise, which could be based on RNR, and/or could be based ondownlink noise, which could be based on SINR. In addition, as discussedabove, the carrier bandwidth could define a plurality of PRBs, and theselected frequency portion could be defined as a frequency-contiguousproper subset of those PRBs. And in that case, the noise of the selectedfrequency portion could be determined based on noise of the PRBsencompassed by the selected frequency portion.

Still further, as discussed above, in an example implementation, thefirst access node could provide 4G LTE service on the first carrier, andthe second access node could provide 5G NR service on the secondcarrier.

FIG. 3 is next a simplified block diagram of an example first accessnode that could be configured to carry out various features describedherein. As shown in FIG. 3 , the example first access node includes awireless communication interface 44, a backhaul communication interface46, and a controller 48, all of which could be integrated togetherand/or communicatively linked together by a system bus, network, orother connection mechanism 50.

In an example implementation, the wireless communication interface 44could support air-interface communication on a first carrier that has acarrier bandwidth, and the wireless communication interface couldtherefore comprise an antenna structure, which could be tower mounted orcould take other forms, and associated components such as a poweramplifier and a wireless transceiver, so as to enable the access node toserve UEs on such a carrier. And the backhaul communication interface 46could comprise a wired or wireless communication module, such as anEthernet network communication module and associated logic, throughwhich the first access node could engage in backhaul communication withvarious other network entities including core-network entities and asecond access node.

Further, the controller 48 could be configured to carry out variousoperations described herein, such as the operations described above inconnection with FIG. 2 , to dynamically reassign RF spectrum from thefirst access node to the second access node. For instance, as shown, thecontroller 48 could include at least one processor 52, such as one ormore general purpose processors (e.g., microprocessors) and/or one ormore specialized processors, and a non-transitory data storage 54 (e.g.,one or more volatile and/or non-volatile storage components (e.g.,magnetic, optical, or flash storage, necessarily non-transitory))storing program instructions 56 executable by the at least one processor52 to carry out those operations (e.g., to cause the first access nodeto carry out the operations).

Various other features described herein can be implemented in thiscontext as well, and vice versa.

FIG. 4 is next a simplified block diagram of an example computing systemthat could carry out various features as described above. In the examplearrangement discussed above, this computing system could be provided atvarious entities, such as the 4G eNB 12 or the like, or an elementmanagement system or other network entity, among other possibilities. Asshown in FIG. 4 , the computing system includes at least one processor58 and at least one non-transitory data storage 60, which could beintegrated or communicatively linked together by a system bus, network,or other connection mechanism 62.

The at least one processor 46 could comprise one or more general purposeprocessors and/or one or more specialized processors. And the at leastone non-transitory data storage 60 could comprise one or more volatileand/or non-volatile storage components, such as magnetic, optical, orflash storage media (necessarily non-transitory). And as further shown,the at least one non-transitory data storage 60 storing programinstructions 64. In a representative implementation, those programinstructions 64 could be executable by the at least one processor 58 tocarry out various operations described herein, such as the operationsdescribed above in connection with FIG. 2 for instance.

Various other features discussed herein can be implemented in thiscontext as well, and vice versa.

The present disclosure also contemplates at least one non-transitorycomputer readable medium (e.g., one or more magnetic, optical, of flashstorage components, necessarily non-transitory) having stored thereon(e.g., being encoded with) or otherwise containing program instructionsexecutable by a processor to carry out various operations as describedherein.

Exemplary embodiments have been described above. Those skilled in theart will understand, however, that changes and modifications may be madeto these embodiments without departing from the true scope and spirit ofthe invention.

What is claimed is:
 1. A method to dynamically reassign radio frequency(RF) spectrum from a first access node to a second access node, whereinthe first access node provides wireless communication service on a firstcarrier having a carrier bandwidth, the method comprising: selecting afrequency portion of the carrier bandwidth to reassign from the firstaccess node to the second access node, wherein the selecting is based ondetermined noise on the frequency portion compared with determined noiserespectively on each of one or more other frequency portions of thecarrier bandwidth, wherein selecting the frequency portion based on thedetermined noise on the frequency portion compared with the determinednoise respectively on each of the one or more other frequency portionsof the carrier bandwidth is based on at least one of uplink noise ordownlink noise; and based on the selecting, reassigning the selectedfrequency portion from the first access node to the second access nodeto be used by the second access node as at least part of a secondcarrier on which to provide wireless communication service, whereby,upon the reassigning of the selected frequency portion, the first accessnode then continues to provide wireless communication service on aremainder of the first carrier.
 2. The method of claim 1, wherein themethod is carried out by the first access node.
 3. The method of claim1, further comprising determining a width of frequency to reassign fromthe first access node to the second access node, wherein the determiningis based on a level of load of the second access node, and whereinselecting the frequency portion of the carrier bandwidth comprises,based on the determining, selecting as the frequency portion of thecarrier bandwidth a frequency portion of the determined width.
 4. Themethod of claim 3, wherein the carrier bandwidth defines a plurality ofphysical resource blocks (PRBs), and wherein the determining the widthof frequency comprises determining a quantity of PRBs.
 5. The method ofclaim 1, wherein the uplink noise is based on reverse noise rise.
 6. Themethod of claim 1, wherein the downlink noise is based on an inverse ofsignal-to-interference-plus-noise ratio (SINR).
 7. The method of claim1, wherein the carrier bandwidth defines a plurality of physicalresource blocks (PRBs), wherein the selected frequency portion isdefined as a frequency-contiguous proper subset of the PRBs, and whereinthe noise of the selected frequency portion is determined based on noiseof the PRBs encompassed by the selected frequency portion.
 8. The methodof claim 1, wherein the first access node provides 4G LTE service on thefirst carrier, and wherein the second access node provides 5G NR serviceon the second carrier.
 9. A first access node comprising: a wirelesscommunication interface supporting air-interface communication on afirst carrier, wherein the first carrier has a carrier bandwidth; abackhaul communication interface; and a controller configured to carryout operations to dynamically reassign radio frequency (RF) spectrumfrom the first access node to a second access node, wherein thecontroller comprises at least one processor, non-transitory datastorage, and program instructions stored in the non-transitory datastorage and executable by the at least one processor to carry out theoperations, and wherein the operations include: selecting a frequencyportion of the carrier bandwidth to reassign from the first access nodeto the second access node, wherein the selecting is based on determinednoise on the frequency portion compared with determined noiserespectively on each of one or more other frequency portions of thecarrier bandwidth, wherein selecting the frequency portion based on thedetermined noise on the frequency portion compared with the determinednoise respectively on each of the one or more other frequency portionsof the carrier bandwidth is based on at least one of uplink noise ordownlink noise, and based on the selecting, reassigning the selectedfrequency portion from the first access node to the second access nodeto be used by the second access node as at least part of a secondcarrier on which to provide wireless communication service, whereby,upon the reassigning of the selected frequency portion, the first accessnode then continues to provide wireless communication service on aremainder of the first carrier.
 10. The first access node of claim 9,wherein the operations additionally include determining a width offrequency to reassign from the first access node to the second accessnode, wherein the determining is based on a level of load of the secondaccess node, and wherein selecting the frequency portion of the carrierbandwidth comprises, based on the determining, selecting as thefrequency portion of the carrier bandwidth a frequency portion of thedetermined width.
 11. The first access node of claim 10, wherein thecarrier bandwidth defines a plurality of physical resource blocks(PRBs), and wherein the determining the width of frequency comprisesdetermining a quantity of PRBs.
 12. The first access node of claim 9,wherein the uplink noise is based on reverse noise rise.
 13. The firstaccess node of claim 9, wherein the downlink noise is based on aninverse of signal-to-interference-plus-noise ratio (SINR).
 14. The firstaccess node of claim 9, wherein the carrier bandwidth defines aplurality of physical resource blocks (PRBs), wherein the selectedfrequency portion is defined as a frequency-contiguous proper subset ofthe PRBs, and wherein the noise of the selected frequency portion isdetermined based on noise of the PRBs encompassed by the selectedfrequency portion.
 15. The first access node of claim 10, wherein thefirst access node provides 4G LTE service on the first carrier, andwherein the second access node provides 5G NR service on the secondcarrier.
 16. A computing system configured to dynamically reassign radiofrequency (RF) spectrum from a first access node to a second accessnode, wherein the first access node provides wireless communicationservice on a first carrier having a carrier bandwidth, the computingsystem comprising: at least one processor; at least one non-transitorydata storage; and program instructions stored in the at least onenon-transitory data storage and executable by the at least one processorto carry out operations including (i) selecting a frequency portion ofthe carrier bandwidth to reassign from the first access node to thesecond access node, wherein the selecting is based on determined noiseon the frequency portion compared with determined noise respectively oneach of one or more other frequency portions of the carrier bandwidth,wherein selecting the frequency portion based on the determined noise onthe frequency portion compared with the determined noise respectively oneach of the one or more other frequency portions of the carrierbandwidth is based on at least one of uplink noise or downlink noise,and (ii) based on the selecting, reassigning the selected frequencyportion from the first access node to the second access node to be usedby the second access node as at least part of a second carrier on whichto provide wireless communication service.
 17. The computing system ofclaim 16, wherein the operations additionally include determining awidth of frequency to reassign from the first access node to the secondaccess node, wherein the determining is based on a level of load of thesecond access node, and wherein selecting the frequency portion of thecarrier bandwidth comprises, based on the determining, selecting as thefrequency portion of the carrier bandwidth a frequency portion of thedetermined width.
 18. The computing system of claim 17, wherein thecarrier bandwidth defines a plurality of physical resource blocks(PRBs), and wherein the determining the width of frequency comprisesdetermining a quantity of PRBs.
 19. The computing system of claim 16,wherein the uplink noise is based on reverse noise rise, and wherein thedownlink noise is based on an inverse ofsignal-to-interference-plus-noise ratio (SINR).
 20. The computing systemof claim 16, wherein the carrier bandwidth defines a plurality ofphysical resource blocks (PRBs), wherein the selected frequency portionis defined as a frequency-contiguous proper subset of the PRBs, andwherein the noise of the selected frequency portion is determined basedon noise of the PRBs encompassed by the selected frequency portion.